chris kyle, a decorated former navy s.e.a.l. who not only survived four combat tours in iraq but was hailed as perhaps the deadliest sniper in u.s. military history, was shot and killed on saturday by a troubled fellow soldier, a man he was trying to help. nbc news chief pentagon correspondent jim miklaszewski joins us with the latest on this. what are police and witnesses saying happened here and where things went so wrong for chris kyle? >> well, police in texas have one suspect in custody. eddie ray routh, a marine corps reservist, 25 years old, who apparently, according to reports, was suffering from ptsd. now, chris kyle and other veterans there in texas would often try to independently help those with ptsd by taking them to shooting ranges to sort of blow off steam. now, according to officials in texas, this was the first time that kyle and his friend had met eddie ray routh at this shooting range about 50 miles outside ft. worth on saturday, when suddenly and allegedly, routh opened fire with a hand gun at point-blank ran